1. Field of the Invention
The present invention relates generally to a device for eliminating jammed papers in an ink-jet printer, for example. More particularly, it relates to a device for smoothly eliminating jammed papers which are generated when papers are fed one by one between a friction roller and a feed roller in a feed cassette loaded with a plurality of papers.
2. Description of the Related Art
In general, the paper feeding structure of an ink-jet printer, for example, can be divided into two types as follows. In one printer structure, a feed cassette (automatic paper feeding device) is slopingly installed at the rear of the printer body (housing) and papers are fed one by one by feed rollers (a friction roller and a feed roller) from the feed cassette loaded with a plurality of papers to a printer head, so that the papers can be ejected into a tray after printing. In the other printer structure, the feed cassette loaded with a plurality of papers is located at the bottom of the ink-jet printer. Individual cut sheets of paper are then conveyed by a pick-up roller and the feed roller and the direction of ejection can be controlled by a guide, so that the papers are fed through the feed roller, conveyed to the printer head, and ejected after printing, in a sequential manner.
In one contemporary design for an ink-jet printer having the first of the two above-noted structures, because the friction roller and the feed roller are closely engaged with each other to convey the sheets of paper, when a sheet of the paper becomes jammed during conveyance, operational problems necessarily occur because the printer must be taken out of operation while jammed paper is removed. Moreover, when the body of the printer is roughly handled or otherwise abused during removal of the jammed paper, a malfunction of the printer frequently occurs.
Examples of early efforts in the art include U.S. Pat. No. 1,385,930 to Scott entitled Sack Feeder, which shows a roller connected to a hinge arrangement to allow the roller to be separated from a facing roller; U.S. Pat. No. 1,578,330 to Lipton, et al. entitled Feeding Mechanism for Printing Presses; and U.S. Pat. No. 2,208,043 to Ormond entitled Offset Printing Machine. Subsequent efforts, namely U.S. Pat. No. 3,298,682 to Gatti entitled Document Aligning And Feeding Device, uses a hinged arm having a roller attached to one end and including a spring, which has its height controlled by a D-shaped cam; U.S. Pat. No. 4,145,181 to Edwards, et al. entitled Apparatus To Facilitate Jam Recovery And Hot Roll Reversal In A Fusing Assembly, which has a multi-lever mechanism arranged to separate rollers and thereby facilitate removal of a paper jam; U.S. Pat. No. 4,522,520 to Takenoya, et al. entitled Device For Adjusting Printing Paper Tension In a Printer, which shows a multi-lever and hinged arm linkage for adjusting the spacing between two rollers; U.S. Pat. No. 4,630,815 to Petersen, et al. entitled Quick Releasing, Pinch Roller Mechanism, which illustrates a quick release mechanism having a lever with a cam mounted is used with a hinged arm arrangement to separate rollers in an effort to remove sheets of paper; U.S. Pat. No. 4,903,954 to Robertson, et al. entitled Sheet Transporting Apparatus; and U.S. Pat. No. 4,973,039 to Jeske, et al. entitled Device For Retailing Sheet Stacks.
More recent efforts, U.S. Pat. No. 5,488,467 to Marentes, et al. entitled Laser Printer Paper Handling System, illustrates another arrangement in which a hinged arm is controlled by a cam so as to move one roller relative to another roller; while U.S. Pat. No. 5,182,861 to Suzuki, et al. entitled Sheet-Driven Type Automatic Drafting Machine, shows a hinged arm and a cam arranged to vary the position of one roller with respect to another roller; and U.S. Pat. No. 5,011,129 to Holbrook entitled Jam Clearance Apparatus For Sheet Feeding Device, illustrates a lever connected to a plurality of hinged arms to allow the separation of rollers to facilitate clearing the apparatus of paper jams. Another recent design, U.S. Pat. No. 5,564,687 to Heiler, et al. entitled Device For Extemporaneously Raising A Transport Roller In A Feeder Of A Sheet Processing Machine, has a hand lever directly rotating the bearing shell that supports a synchronizing roller. I have found that typically these designs employ multiple linked components in an endeavor motivated by different concerns, to simply separate a pair of rollers propelling the printed medium along its path through the device